With his smashing victory in Tuesday’s primary to become the Democratic candidate for the U.S. Senate in Illinois, the 42-year-old state senator and University of Chicago law instructor stands poised to enter the national stage, and history. If elected _ and the odds now favor him _ he would be only the third black senator since Reconstruction.

“The moment he sets foot in the U.S. Senate he is going to be a national figure, not only national but international,” says U.S. Rep. Janice Schakowsky, an early supporter, whose district embodies the “lakefront liberals” _ mostly white and Jewish _ who are part of Obama’s base.

Tall, fresh and elegant, Obama is certain to be an overnight sensation in national Democratic circles.

He is their best chance to pick up a Senate seat now in Republican hands (the incumbent, Peter Fitzgerald, did not seek re-election). But he is also the candidate from central casting for a new generation of national black leadership, still moored in the values of the civil rights movement but in tone and approach more cool than hot.

This was the political year in which the Rev. Al Sharpton of New York ran for president in an apparent bid to become the new Jesse Jackson, without much success. Instead, it is likely to be Obama who becomes the rising star _ with the active support of both Jackson and his son, Jesse Jr., a congressman from Chicago’s South Side.

And should he make it to the Senate, Obama would be a multicultural figure unlike any to have served in the world’s most exclusive club, a man peculiarly in sync with the nation’s changing zeitgeist on race.

As he wrote a decade ago in a memoir, “Dreams From My Father: A Story of Race and Inheritance,” his mother, a Kansan, was “white as milk”; his father, a Kenyan who left when Barack was 2 and returned to Africa, was “black as pitch.”

“In 1960,” he wrote, “the year that my parents married, miscegenation still described a felony in over half the states in the Union.”

Obama grew up in both Hawaii and Indonesia, where he attended Catholic and Muslim schools (his father’s father was a Muslim but Obama is a member of Chicago’s giant Trinity United Church of Christ). After earning a political science degree from Columbia University he went to Harvard Law School, where professor Laurence Tribe remembers him as “among the most intellectually creative and energetic students I can recall.” He was elected the first black president of the Harvard Law Review.

After law school, he moved back to Chicago, where he had spent years as a community organizer. And there, through seven years in the state Senate, he has emerged, outside the machine and remarkably unscarred, from the dense thicket of Chicago politics and especially the precincts of the black South Side, arguably the most self-consciously black political space in the nation.

“What is remarkable about this race has been the degree to which Barack has developed an appeal that crosses racial, geographic and economic lines,” said David Axelrod, the Chicago political consultant who advised the Obama campaign.

As Obama puts it, “I’m rooted in the African-American community, but I’m not limited by it.”

He acknowledges that his biography is “exotic” in the context of American politics. But the background that a few years ago would have effectively disqualified him from seeking statewide office now carries cachet in a nation seeking guidance amid its rapidly growing diversity.

“He is the embodiment of the multicultural society, the kind of multicultural society we have become, because he himself is multicultural,” said Joe Moore, who is white and represents the very diverse Chicago neighborhood of Rogers Park on the Board of Aldermen.

To a unique degree, Barack Obama (bah-ROCK oh-BAH-ma) stands as both a symbol and a champion of black aspirations and a sort of Tiger Woods figure, a harbinger of a politics beyond race.

“Chicago is racially charged to the nines,” Tracy Ullman, a new mother, said after shaking Obama’s hand at Lou Mitchell’s, a popular Chicago diner, the day before the election. But in Obama, Ullman, who is white and has worked in TV production and publishing, sees someone who defuses those tensions.

“He’s got a lovely personality, a charm and charisma,” she said.

In fact, Obama’s campaign was dogged by the question _ now answered in the affirmative _ of whether he was “black enough” for black voters.

“Who in the hell is black enough?” asked R. Eugene Pincham, a retired state appellate court judge and lion of black politics in Chicago, who encouraged Obama to run for the Senate. “Black folks have been voting for white folks for as long as black folks could vote. Now we’ve got to make white folks vote for black folks, and I thought Obama was the person who could attract votes in the white community.”

Pincham continued: “He’s got a white mama and a black daddy who wasn’t an American _ that sells to white folks. He looks somewhat Oriental and he looks black, he is black. But he also has this tone that distinguishes him from the typical black, and yet he’s black.”

Moreover, “he could have done the Tiger Woods thing, but didn’t.” Pincham was referring to Woods’ description of himself as “Cablinasian” (for Caucasian, black, Indian and Asian), which offended many blacks.

By contrast, Obama wrote in his memoir,“I ceased to advertise my mother’s race at the age of 12 or 13, when I began to suspect that by doing so I was ingratiating myself to whites.”

For now, in the wonderland of ethnic politics that is Chicago, Obama has proved expert at playing the game at an even higher level.

In quick succession on Monday, he campaigned among black, Chinese and white senior citizens. At the Chinese senior center, he explained that he had lived in Asia and that his half-sister is married to a Chinese Canadian and expecting. At the Breakers elderly housing, where the crowd, including many Jews, was a sea of Obama buttons, he noted that his first name means “one who is blessed. It means the same in Swahili as `baruch’ in Hebrew. Both have Semitic roots.”

If elected, Obama would reclaim the seat lost six years ago by Carol Moseley Braun, who was the second black senator since Reconstruction, the first being Edward Brooke, a Republican from Massachusetts. There are no blacks in the Senate now and no other black Democratic prospects this year, though there are two black Republicans seeking Senate seats against long odds in Georgia and Indiana.

Meanwhile, Obama faces an attractive Republican candidate in Jack Ryan, an investment banker turned teacher on the South Side, who is also handsome, Harvard-educated and in his early 40s.

It is certain to be a high-profile race, and, in national political circles, the until-now obscure name of Barack Obama will be tripping off people’s tongues.

A few weeks ago, Schakowsky joined 18 members of the Black Caucus who met with President Bush about Haiti. On their way out, she said, the president noticed her “Obama” button and asked about it.

“I really do think he thought it said, `Osama,”’ Schakowsky recalled. “I said, `No, Obama, Barack Obama, he’s running for the United States Senate from Illinois.’